Abdisalan Hussein Ali, a 22-year-old Somali who grew up in America and is believed to be one of two suicide bombers who struck African Union forces on Saturday, called for jihad against Australia in a recording obtained byThe New York Times. In the recording, Ali repeats the Al-Qaeda mantra that jihad is an obligation from God incumbent on every Muslim and then calls for his “brothers and sisters” to fight jihad in America, Canada, England, “anywhere in Europe”, in Asia, Africa, China and Australia.

As noted in the Times article, Ali was seemingly an average, well-adjusted American teenager when he vanished, surfacing later in the surface of Somalia’s al-Qaeda linked al-Shabab organisation.

During high school, he sold sneakers out of his locker to make money to help support his family. He lifted weights, and his friends called him “Bullethead.” He was elected president of the school’s Somali Student Association, and he later became a caseworker at a prestigious law firm. At the University of Minnesota, he majored in chemistry and held a part-time job as a security guard at the management school there.

“He was a highly motivated kid,” said a fellow student, an upperclassman who became his mentor. “He wanted to change lives.”Why and when he turned to Islamic militancy is unclear.

A friend of Mr. Ali’s, who attended middle school and then college with him, said they were part of a tight-knit group of Somali-Americans who grew up together and would talk about Somalia and debate politics.

“There was a desire in all of us, that our parents always talk about, the great Somalia,” the friend said, who did not want to be identified for fear of being questioned by the F.B.I. Mr. Ali was not her first Somali friend to join the Shabab, she said, nor the first to die as a member of the group.

Given al-Shabab’s implication in previous terror plots in Australia, their influence should be a matter of concern for Australian authorities.